1. Field of the Invention
The present invention relates to a USB 3.0 host with low power consumption and a method thereof, and particularly to a USB 3.0 host and a method thereof that can reduce power consumption of the USB 3.0 host according to a predetermined condition between the USB 3.0 host and a USB peripheral device.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a diagram illustrating a USB 3.0 host 100 connected to a USB 3.0 peripheral device 110 through a composite cable 120. As shown in FIG. 1, a physical layer of the USB 3.0 host 100 is divided into a super speed circuit 102 which supports a super speed transmission (USB 3.0), and a non-super speed circuit 104 which supports a non-super speed transmission (USB 2.0), where the non-super speed circuit 104 further includes a high speed circuit 1042, a full speed circuit 1044, and a low speed circuit 1046. Similarly, the USB 3.0 peripheral device 110 (not including a USB 3.0 hub) also has a super speed circuit 112 which supports the super speed transmission, and a non-super speed circuit 114 which supports the non-super speed transmission. The super speed circuit 102 of the USB 3.0 host 100 communicates with the super speed circuit 112 of the USB 3.0 peripheral device 110 through a first connection line 122 of a composite cable 120, and the non-super speed circuit 104 of the USB 3.0 host 100 communicates with the non-super speed circuit 114 of the USB 3.0 peripheral device 110 through a second connection line 124 of the composite cable 120. It should be noted that the super speed circuit 102 and the non-super speed circuit 104 of the USB 3.0 host 100 do not simultaneously communicate with the super speed circuit 112 and the non-super speed circuit 114 of the USB 3.0 peripheral device 110 through the first connection line 122 and the second connection line 124 of the composite cable 120, respectively. In addition, a non-USB 3.0 peripheral device 130 only has a non-super speed circuit (not shown in FIG. 1) which supports the non-super speed transmission. Therefore, the non-super speed circuit of the non-USB 3.0 peripheral device only communicates with the non-super speed circuit 104 of the USB 3.0 host 100 through the second connection line 124 of the composite cable 120.
As shown in FIG. 1, in the prior art, when the USB 3.0 peripheral device 110 is connected to the USB 3.0 host 100, regardless of transmission data quantity between the USB 3.0 host 100 and the USB 3.0 peripheral device 110 and a power management policy of the USB 3.0 host 100, the super speed circuit 102 and the non-super speed circuit 104 of the USB 3.0 host 100 are always turned on. That is to say, the USB 3.0 host 100 does not determine to utilize the super speed circuit 102 to connect the super speed circuit 112 of the USB 3.0 peripheral device 110 and turn off the non-super speed circuit 104, or to utilize the non-super speed circuit 104 to connect the non-super speed circuit 114 of the USB 3.0 peripheral device 110 and turn off the super speed circuit 102 according to the transmission data quantity between the USB 3.0 host 100 and the USB 3.0 peripheral device 110 and the power management policy of the USB 3.0 host 100. Thus, the USB 3.0 host 100 unnecessarily wastes much power consumption.